Atlas of pathology
Where: respiratory system, nasal cavity
This is progressive atrophic rhinitis, which is due to a combination of two bacteria working together, Pasteurella multocida type D and Bordetella bronchiseptica. It is also unusual in that these bacteria have toxins that can specifically attack the bones and cartilage of the nasal turbinate bones. Most bacteria and viruses only attack soft tissues. Affected pigs are usually 6 to 12 weeks-old with snorting and sneezing, a serous to thick mucoid nasal discharge, and some bloody mixtures in this sneezing nasal discharge. Pigs affected for longer periods grow slowly and have the noticeable deformities of their nose with a wrinkled nose or a twisted nose and snout– enabling these pigs to sniff around corners. The extent of damage to the nose may be examined in dead pigs, by using a saw to cut across the upper face, at the level of the first pre-molar tooth. This disease is now rare, due to the use of vaccines and restocking with clean pigs, which means that a farm can become free of this disease and it seems to rarely return. The disease is now mainly seen on older farms where piglets are derived from various sources of non-vaccinated gilts.